[PATCH v2 1/6] mm/page_io: convert write completion handlers to folios

[Tal Zussman]

Convert swap_write_end() and swap_fs_write_complete() to operate on
folios directly instead of going through the folio-compat page APIs.
This removes calls to end_page_writeback() and set_page_dirty(), and the
last caller of ClearPageReclaim(), saving two calls to compound_head()
per folio on the write error path.

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
Signed-off-by: Tal Zussman <tz2294@xxxxxxxxxxxx>
---
 mm/page_io.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index 88962571cb93..fbcf58ff292d 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -497,13 +497,13 @@ static void swap_write_end(struct swap_iocb *sio, bool failed)
 	int p;
 
 	for (p = 0; p < sio->nr_bvecs; p++) {
-		struct page *page = sio->bvecs[p].bv_page;
+		struct folio *folio = bvec_folio(&sio->bvecs[p]);
 
 		if (failed) {
-			set_page_dirty(page);
-			ClearPageReclaim(page);
+			folio_mark_dirty(folio);
+			folio_clear_reclaim(folio);
 		}
-		end_page_writeback(page);
+		folio_end_writeback(folio);
 	}
 	mempool_free(sio, sio_pool);
 }
@@ -514,16 +514,16 @@ static void swap_fs_write_complete(struct kiocb *iocb, long ret)
 	bool failed = ret != sio->len;
 
 	if (failed) {
-		struct page *page = sio->bvecs[0].bv_page;
+		struct folio *folio = bvec_folio(&sio->bvecs[0]);
 
 		/*
 		 * In the case of swap-over-nfs, this can be a temporary failure
 		 * if the system has limited memory for allocating transmit
-		 * buffers.  Mark the page dirty and avoid
+		 * buffers.  Mark the folio dirty and avoid
 		 * folio_rotate_reclaimable but rate-limit the messages.
 		 */
 		pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n",
-				   ret, swap_dev_pos(page_swap_entry(page)));
+				   ret, swap_dev_pos(folio->swap));
 	}
 
 	swap_write_end(sio, failed);

-- 
2.39.5